Guide means for weft inserting elements



Jan. zo, 1970 R. DEWAS 3,490,498

GUIDE MEANS FOR WEFT INSERTING ELEMENTS 4 Filed May 23, 1967 2 Sheets-Sheet l '9 10 69 IX 24A 73 8 x 72 6 Fig. 2 Fig. 4 Fig. 3

A Qi RAV/40N vfwAs 32 www1-0R Jan. 20,*1970 R. DEWAs' 35490,'-498 GUIDEMEANS FOR wEFT INSERTING ELEMENTS Filed May 23, 1967 2 Sheets-Sheet 2 S E. Aavn M015 ETEN myw? F di .Q V T. Dvrwf. m@ w M MM Vl D United States Patent O 3,490,498 GUIDE MEANS FOR WEF'I INSERTING ELEMENTS Raymond Dewas, 120 Boulevard de Saint Quentin, Amiens, Somme, France Filed May 23, 1967, Ser. No. 640,653 Claims priority, applicatitr Luxembourg, May 25, 1966,

Inf. c1. Dosti 47/00, 49/60 U.S. Cl. 139-122 3 Claims ABSTRACT OF THE DISCLOSURE The invention relates to weaving machines with external weft supply by large bobbins situated outside the shed.

It concerns mainly the guidance of the needles utilised especially on looms of great width, which needles are usually composed of a flexible ribbon and a rigid part which itself comprises a needle body and a head, the forward part of the said ribbon being fixed beneath the lower face or sole of the said needle body.

In a conventional type of machine of this kind, a drive wheel having teeth or projections meshes in perforations of the ribbon and imparts a reciprocating movement to the needle; outside the shed, the edges of the ribbon are engaged in a rectilinear slideway which is prolonged by an arch or other reversing element which directs the ribbon towards the bottom of the machine, while inside the shed the said edges are engaged in grooves of guides of finger form. Such provisions are described and represented especially in the Applicants U.S. Patent No. 3,232,321.

These machines are utilised at higher and higher running speeds; this increase of speed, and consequently the increase of speed of the ribbon, causes significant heating especially of the arch, because an effect similar to that of a band brake occurs between the ribbon and the arch.

This increase of the band brake effect subjects the ribbon between the drive wheel and the arch to significant tractions and compressions, so that the radial component of the meshing force further presses the ribbon against the guide plates which limit its rise, and the frictional force resulting from this is added to the resistance to meshing. This causes a wear on the meshing flanks of the teeth of the wheel and the flanks of the perforations of the ribbon and also the upper edges of the latter, fatigue of the elements which drive the wheel and a loss of drive force.

The invention has the purpose of providing new means for the guidance of the ribbon which improve the sliding of the ribbon and therefore are heated noticeably less than those formed especially by the metallic surfaces of the arch and its covering strip.

To this end, according to the invention, the major part of the guide means of the ribbon provided between the selvedge of the fabric and the lower end of the return element is constituted by elements of dry solid lubricants which possess the advantage of considerably improving the sliding of the ribbon in its guides.

Moreover the very iine particles which these elements release under the action of the friction of the ribbon, although in minute quantity, ensure a dry lubrication of the ribbon; certain of these very line particles adhere to the outer surfaces of the ribbon and upon the flanks of its nr' ice perforations, so that the function of the ribbon and its mesh with the drive wheel are improved.

When certain of the ribbon guides, in any part whatever of the path of the ribbon, are not made of solid lubricant, particles of the said lubricant entrained by the ribbon are deposited on the said guides; thus the ribbon functions under optimum conditions over the whole length of its course.

More generally it can be said that according to the invention a dry lubrication is obtained of the edges and ends of the ribbon and of the flanks of the meshing perforations thereof of the teeth of the drive wheel, of the plates which prevent rising of the ribbon in the meshing zone, and of all the guide means of the ribbon throughout its path. In fact the general operation of the inserter is improved, especially when the ribbon is made of Celoron. This is made evident by the reduction of the heating and absorption of drive power, which is the certain index of a reduction of the coefficient of friction.

These elements of solid lubricant can be either strips applied or stuck to the guide surfaces, or pieces having their own securing, or pieces reduced to the minimum of material necessary and permanently placed in supports serving for their securing.

Among the means for guidance of the ribbon there is especially the arch which returns the ribbon towards the bottom of the machine.

In one form of embodiment the arch comprises a groove forming a slideway for the ribbon. This groove is closed by a covering band of steel strip. Such an arrangement is described and represented in the U.S. Patent No. 3,232,- 321, in FIGURE 7. According to the invention the guide elements are constituted by a band of solid lubricant stuck or even stretched over the bottom of the groove of the arch, and by another band of solid lubricant stuck on the inner face of the covering.

In another form of embodiment the arch comprises a wider groove and the guide elements are constituted by two thicknesses of solid lubricant, superimposed in the groove of the arch, between which thicknesses the ribbon slides in a slideway of corresponding dimensions formed in one of the mutually opposite faces of the said thicknesses.

In another form of embodiment the arch possesses a support face for the guide elements of solid lubricant, protruding from which there is a central rib through which gripping bolts for the said guide elements pass, each of which bears at the same time against one of the faces of the said rib and against the corresponding part of the said support face of the arch, guide grooves for the ribbon being formed in the mutually opposite faces of the xed elements on either side of the central rib.

In variance of the preceding form of embodiment, the securing of the guide elements on the arch is advantageously effected in such manner as automatically to ensure a good seating of the said elements both on the central rib and on the-support face of the arch.

In one particular form of embodiment the plates which, in the meshing zone of the drive wheel, limit the rise of the ribbon are constituted by bars of solid lubricant, preferably of square section and pierced with securing holes in central planes, so that their different faces can be used successively after partial wear thereof as the result of long service.

The invention will be better understood on reading of the following description and examination of the accompanying drawings which show, by way of non-limitative examples, some forms of embodiment of guide devices for the ribbon of an inserter of a weaving machine. In the drawings:

FIGURE 1 is a front elevation view showing the lefthand part of a weaving machine and illustrates the application of the invention.

FIGURE 2 relates to a different embodiment and is a cross-section of the peripheral part of an arch with covering of steel strip, with addition of bands of solid lubriant upon the two cylindrical guide surfaces for the rib- FIGURE 3 is a different embodiment showing a crosssection of the peripheral part of an arch, the guides of which comprise two superimposed thicknesses of solid lubricant.

FIGURE 4 is a partial section of the arch along the line IV-IV in FIGURE l, but on a larger scale.

FIGURES 5, 6, 7 and 8 are cross sections of different embodiments being variants of FIGURE 4 in which the manner of clamping of the guide elements automatically ensures their good seating on the bearing surfaces of the arch, FIGURE 8 further representing guide elements of solid lubricant inserted into supports.

FIGURES 9 and 10 are cross-sections, on dierent scales, along the lines IX-IX and X-X respectively, in FIGURE 1.

FIGURE l1 is a cross-section of a different embodiment, being variant of FIGURE 10.

The slay is designated by 1, while the sword 2, driven in known manner by the crankshaft (not shown), oscillates about a horizontal shaft 3 supported by the chassis 4 of the machine. The slay 1 in known manner carries guides for the flexible ribbon 6, the forward end of which (not shown in the drawing) carries the needle body and head. A frame 7 is fixed `at 8 to the upper part of the slay. An arch 9 is fixed to the upper part and the lower part of the frame 7 at 10 and 11 respectively; it effects the guidance of the ribbon 6 in its return path towards the lower part of the machine where it is received in a conduit 12.

In the form of embodiment as represented, the frame 7 comprises two inclined uprights 7A and 7B which are fixed 'by their lower ends at 13 and 13 respectively on the top of an oscillating casing 14 of the type as described in the applicants U.S. Patent No. 2,688,344. This casing contains a cam 15 having a groove 16 with sinusoidal course in which there is engaged la roller 17 mounted on the lower end of an oscillating lever 18 carried by a spindle 19 at right-angles to the shaft 3 and supported by the oscillating casing 14. The cam 15 is fast with the shaft 3 to which a rotational movement of one revolution is imparted per revolution of the crankshaft. The upper end of the lever 18 is equipped with a toothed sector 20 in mesh with a pinion 21 fast with a toothed wheel 22 the teeth of which engage in the central perforations of the ribbon 6. The toothed wheel 22 and the pinion 21 are carried by a spindle 23 fixed in the supports 24A and 24B which are fast with the frame 7 and the arch 9.

The rotational movement of the shaft 3 thus causes an oscillating movement of the toothed sector 20 and consequently an alternating rotational movement of the toothed wheel 22 which in turn imparts its reciprocating movement to the ribbon 6'.

The construction which has just been described hitherto is of known type. The invention consists in a particular realisation of the various guide elements of the ribbon 6 and especially the arch 9.

In the form of embodiment as represented in FIGURE 2, the arch 9 and its covering 25 of steel strip are comparable with those of known type as described in the applicants French Patent No. 1,370,335 of Sept. 26, 1963, but the groove 26 of the arch 9 is given an extra depth corresponding to the thickness of a band 27 of solid lubricant stuck or stretched to the bottom of the said groove, another band 28 of solid lubricant being stuck on the inner face of the covering 25. The bands 27 and 28 can for example be of polytetrauoroethylene.

In FIGURE 3, guide segments of solid lubricant, for example graphite, such as 29 and 30, have the form of portions of cylindrical crowns. They are fixed one upon the other and against the cylindrical surface of the bottom of a wide groove 31 defined by two flanges 32 of the arch 9, by means of screws such as 33. The recess for the ribbon 6 is preferably formed in only one of the two mutually facing segments; in the example the ribbon 6 lslides in a groove 34 formed in the outer face of the segment 29, and against the cylindrical inner surface of the segment 30, which is applied against the outer face of the segment 29.

In the form of embodiment as represented in FIG- URES l and 4, the guide means for the ribbon 6 on the arch are constituted by blocks or segments of solid lubricant, one series of these blocks such as 35 being placed on one side of a central rib 36 of the arch, and a second series of blocks such as 37 being placed on the other side. In the example the segments, six in number on each face, are disposed one behind the other and are fixed on the arch by bolts 38. The position of the segments is ensured by the following arrangement: the arch 9 possesses an external surface 39A and 39B of cylindrical form upon which the central rib 36 with parallel faces protrudes. Each of the guide segments, 35 or 37, has a face 40A or 40B of cylindrical form which is applied exactly against the corresponding part of the cylindrical face 39A or 39B of the arch, and a plane face 41A or 41B which bears aginst the plane lateral corresponding face of the central rib 36. Each bolt 38 thus passes at the same time through two guide segments such as 3S and 37 and the central rib 36.

The mutually opposite faces of the guide segments 35 and 37 each possess a groove 42A or 42B in the form of an arc of a circle, of suitable dimensions to ensure perfect guidance of the ribbon 6, which is usually formed in two thicknesses.

As shown in FIGURE 1, each of the guide segments such as 35 or 37 is fixed on the arch 9 by means of the two bolts 38.

In FIGURE 5 the segments 43 and 44 have a general form analogous with that in FIGURE 4; two clamps 45 for each bolt 38 comprise an oblique part 46 in cOntact with a part 47 of corresponding inclination of the segtment; at the other end of the clamp 45 a flange 48 bears upon a plane part 49 of the arch, which by means of a rim 50 prevents the clamp 45 from rising on tightening of the bolt 38, under the effect of the ramps 46 and 47; the inclination of these ramps gives an oblique clamping resultant which applies the segment simultaneously upon its two bearing surfaces 51 and 52 of the arch.

In FIGURE 6 the lateral faces 53 of the central rib 54 of the arch -9 are conical so that the segments 55- and 56, the corresponding faces of which are equally inclined, are thrust on tightening against the cylindrical faces 57A and 57B of the arch.

In FIGURE 7 the segments 58 and '59 comprise receiving orifices such as 60 for Screws 61 the threads of which engage in oblique tapped holes 62 of the arch; the inclination of the screws 61 ensures clamping in two directions, radial and transverse, as in the previous form of embodiment.

In FIGURE 8 the clamping principle is the same as in FIGURE 7, but the guide element 63 of solid lubricant is reduced to minimum volume and inserted into a metallic support 64 by moulding, sticking or any other means. The screws 65 pass freely through oblique holes 66 of the arch and are screwed into the tapped holes 67 of the metallic support 64. On one of the sides, by way of variant, the element 63 is replaced by two bands 68A and 68B of solid lubricant.

In the various forms of embodiment the segments may be in any desired number.

In FIGURE 9 there may be seen especially the ribbon 6, its toothed drive wheel 22 and two bars 69 and 70 which cover the edges of the upper face of the ribbon in order to limit the rise thereof under the action of the radial reaction of the teeth of its drive wheel.

In the example as represented these bars are of solid lubricant, for example graphite. Each of them is of square section and is tixed on the top of the frame 7 by screws such as 71 which pass through holes formed in a central plane of the said bar. The latter also has holes for the passage of fastening screws in the other central plane perpendicular to the former, so that the said bar can be xed at on its diierent faces against the top of the frame 7, permitting of offering a new surface for the sliding of the ribbon after partial wear of one face.

In FIGURE l there are represented guide elements for the ribbon 6 which are situated between its drive wheel and the first guide blocks such as (FIGURE l) intended to penetrate into the shed in the insertion of each pick. These guide elements are constituted by a conduit 72 in which the ribbon 6 slides, being held upwards by two plates 73 and 74 which cover its edges. This conduit and these plates are xed on the top of the frame 7 by screws such as 75. The cond-uit 72 is constituted by a piece of solid lubricant, for example of graphic, of parallelepipedic form, in the upper face of which there is formed a groove 76 of rectangular section substantially equal to the section of the ribbon. A similar groove can advantageously be formed in the lower face; if the rst groove is worn the turning of the conduit permits of putting a fresh guide into service.

FIGURE ll represents a variant of FIGURE in which the plane surface on which the ribbon slides is constituted by a band 77 of solid lubricant, for example polytetrauoroethylene or other appropriate material, stuck or stretched on a rigid plate 78. The plates 79 and 80 covering the edges of the ribbon are also lined with bands of solid lubricant 81 and 82 in their part which is in contact with the ribbon.

The invention is not of course limited to the forms of embodiment as described and represented; modifications can be made therein without departing from the scope of the invention.

At the commencement of the description mention was made of an arch for guidance of the ribbon, but it is understood that the invention is applicable to all elements for return of the said ribbon, irrespective of their design, their arrangement, and their number, and of the manner in which the ribbon is driven.

What I claim is:

1. In a shuttleless loom in which the weft is supplied from stationary packages to reciprocating weft inserting means, said weft inserting means comprising flexible tape members and guide means constituting a slideway through which said tapes reciprocate, said guide means comprising means forming a groove, a strip covering said groove, a band of solid lubricant located in the bottom of said groove and another band of solid lubricant -xed to the inner surface of said strip.

2. In a shuttleless loom in which the weft is supplied from sationary packages to reciprocating weft inserting means, said weft inserting means comprising flexible tape members and guide means constituting a slideway through which said tapes reciprocate, said guide means comprising a central rib, guide elements of dry solid lubricant having shaped grooves located on opposite sides of said rib with said grooves in facing relationship and clamping bolts extending through said guide elements and said central rib retaining said elements in xed relative position.

3. In a shuttleless loom in which the weft is supplied from stationary packages to reciprocating weft inserting means, said weft, inserting means comprising flexible tape members and guide means constituting a slideway through which said tapes reciprocate, said guide `means comprising means forming an enclosed groove, said means comprising two bands of solid lubricant located in contacting relationship along their length and width with said groove being formed in one of said bands.

References Cited UNITED STATES PATENTS 2,604,123 7/1952 Budzyna et a1. 139-127 2,310,403 10/1957 Sanderson et a1. 139-122 FOREIGN PATENTS 541,343 10/1955 Belgium.

HENRY S. JAUDON, Primary Examiner U.s. C1. X.R. 139-4123, 18s 

